This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Since 2005 the long-term goals have been two-fold: 1) to positively influence the development of and risk for overweight/obesity through increased participation in physical activity (PA) in American Indian and rural schoolchildren using a school community-based participatory research approach (CBPR);and 2) to evaluate the effectiveness of an internet-delivered PA behavior modification program on PA levels, cardiometabolic disease risk factors, and psychosocial/behavioral variables in middle-aged overweight/obese adults residing in rural communities. Goal 1 [unreadable]A CBPR approach was used to build and implement a web-based PA tracking tool (pedometer or time) in an American Indian school district. Select Youth Risk Behavior Survey items and body mass index were evaluated longitudinally (web-based tracking tool;2006-2008) in conjunction with implementation and development (on-going) of a culture/population specific school-based PA intervention. The school-based intervention and web-based tool were implemented and are currently being evaluated in a second larger rural (predominantly Caucasian) school community using a CBPR approach. Goal 2 [unreadable]PA and cardiometabolic disease risk factor efficacy testing (randomized control trial;RCT) of a commercially available, internet-delivered, theory-based, physical activity behavior change program were completed. Findings demonstrated strong short-term outcomes for PA levels and central adiposity in overweight/obese adults but significant PA relapse occurred at one-year. Evidence-based revisions were made to the PA behavior change program to include: 1) enhanced internet interactivity and engaging content;and 2) tapered post-intervention weaning from the active intervention. A RCT testing the efficacy of these recently implemented evidence-based modifications to the internet-delivered PA intervention is nearly complete (April 2009).